Heat dissipated from an engine in operation can cause hot spots on its surface. If the outer surface of an engine is situated in a place where oil leakage is possible, then when leaked oil comes in contact with the hot spots above the oil’s autoignition temperature, it can ignite spontaneously. Consider an engine cover that is made of two large parallel plates. The heat flux from the engine is 125 W/m² and heating the bottom plate to 300°C. To prevent fire hazard in the event of oil leak on the engine cover, the top plate of the engine cover should be kept below 150°C. Determine whether the top plate of the engine cover is below 150°C, if not determine the number of radiation shields that should be positioned in parallel between the plates. Assume all the surfaces have the same emissivity of 0.3.

Transcribed Image Text:

Radiation shields 125 W/m² Top surface, T₂, 8 Bottom surface T₁ = 300°C, &